Warren Gillis added 11 points and Shivaughn Wiggins had 10 points and six assists for the Chanticleers (15-5, 6-2 Big South), who outrebounded Presbyterian (7-14, 3-5) 44-22, including 19-3 on the offensive glass. Tristan Curtis had a season-high 10 rebounds.
Coastal Carolina made just 7 of 30 field goal attempts in the first half, but converted 14 offensive rebounds into nine second-chance points and took a 26-20 lead into halftime.
A dunk by DeSean Murray pulled Presbyterian within three with 13:35 to play, but a 3-pointer by Gillis sparked a 17-4 run which gave Coastal Carolina a 50-34 lead when Diagne hit a 3 with 7:40 remaining.
Jordan Downing led the Blue Hose, who trailed by double digits the rest of the way, with 17 points.